High-lightweight remote sensing camera focal plane supporting structure and focal plane

Abstract

The invention discloses a high-light-weight remote sensing camera focal plane supporting structure. The structure comprises a focal plane main bearing; the focal plane main bearing comprises a composite rod, a focal plane side support and an interface module; the three composite rods are parallel, the two ends of each composite rod are fixedly connected with the two focal plane side supports respectively, and three connecting points of the three composite rods and the same focal plane side support are distributed in a triangular shape. And the interface module is arranged on the composite rod and is used for connecting the functional module. The invention further provides a high-light-weight remote sensing camera focal plane which comprises the supporting structure, a splicing reflector, a detector, a back circuit and a thermal control module, wherein the splicing reflector, the detector, the back circuit and the thermal control module are fixed to the supporting structure. The supporting structure is high in specific stiffness, high in temperature stability and high in interface adaptability, the mechanical burden of the camera body is greatly relieved, and resources of the whole machine are saved.

Description

Technical Field

[0001] The invention relates to a highly lightweight supporting structure and a focal plane for a long linear array focal plane of a remote sensing camera, and belongs to the technical field of space optical remote sensors. Background Art

[0002] With the development of space remote sensing technology, human beings have more and more demands for the detection of ground scenes. The corresponding linear field of view of the focal plane of remote sensing cameras is getting longer and longer, and the number of spectral bands of detectors is increasing, in order to meet the needs of ultra-wide and multi-spectral detection and give full play to the detection capability of a single payload. Ultra-long linear array detection is achieved by splicing multiple detectors on a focal plane. At present, the splicing method with the best imaging quality is optical field of view splicing. That is, a splicing reflector is set in the imaging optical path to split the linear array direction field of view into reflection and transmission fields of view arranged periodically in sequence. The detectors are staggered in the reflection and transmission areas to receive light from different fields of view, meet the full field of view light reception and back circuit layout, and thus realize ultra-long linear array detection imaging. Due to the use of optical splicing, the reflection field of view needs to be set with corresponding splicing reflectors, and each detector has a back circuit of corresponding scale behind it. That is, in addition to supporting the necessary detectors, the entire focal plane support structure also supports the splicing mirrors in the reflection area. The back circuit of each detector also supports the corresponding thermal control components, such as heat pipes, thermistors, and heat collection adapters. The entire focal plane is a highly integrated component in terms of optics, mechanics, electricity, and heat. When the length of the linear array increases, the weight of the focal plane component will increase sharply, and the amount of thermal expansion will also increase proportionally, which poses a great challenge to the mechanical and thermal stability of the focal plane itself, as well as the carrying capacity of the optical and mechanical body. The use of a focal plane support form with higher lightweight and higher mechanical and thermal stability is of great significance to the development and application of future long-array remote sensing cameras.

[0003] At present, the existing focal plane support structure at home and abroad is basically a frame slot structure, that is, the structure is a slot-shaped structure with an open side on a long strip, and windows are opened on the two long sides adjacent to 90 degrees as the light-passing port for the detector to receive light. The spliced ​​reflector is installed on the inner wall of the frame slot, and the detector and the back circuit are installed on the outer wall of the frame slot. Common focal plane frame materials are Invar, cast titanium, and carbon silicon carbide. The Invar focal plane frame has high thermal stability, but due to the high density of Invar, the overall specific stiffness of the frame is poor, which is not suitable for long-line array focal planes, and the material is not easy to process; the cast titanium focal plane frame has a slightly better specific stiffness than the Invar frame, but poor thermal stability. The longer the linear array, the more obvious the thermal expansion linearity, so it is not suitable for long-line array focal planes; the carbon silicon carbide focal plane frame has high thermal stability and high specific stiffness, but poor interface matching, and needs to be inlaid with metal embedding as an optomechanical, electrical and thermal interface, which increases the overall weight, and the preparation cost of carbon silicon carbide is relatively high. Therefore, high specific stiffness, high temperature stability and strong interface adaptability are the three key points in focal plane design. Meeting these three points at the same time while taking into account material cost and preparation process is the technical difficulty in the focal plane design of space cameras. Summary of the invention

[0004] The purpose of the present invention is to overcome the above defects and provide a highly lightweight remote sensing camera focal plane support structure and focal plane, which solves the technical problem that the traditional frame slot structure cannot take into account the three requirements of high specific stiffness, high temperature stability and interface adaptability of the focal plane design. The support structure of the present invention has high specific stiffness, high temperature stability and strong interface adaptability, which greatly reduces the mechanical burden of the camera body and saves the resources of the whole machine.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A highly lightweight remote sensing camera focal plane support structure, comprising: a focal plane main bearing force;

[0007] The main bearing force of the focal plane includes composite rods, focal plane side supports and interface modules;

[0008] The three composite rods are parallel, and both ends of each composite rod are fixedly connected to two focal plane side supports respectively, and the three connection points of the three composite rods and the same focal plane side support are distributed in a triangle;

[0009] The interface module is arranged on the composite rod and is used for connecting the functional modules.

[0010] Further, the composite rod is a hollow composite tube with a square cross section;

[0011] The composite rod is formed by staggered plying of carbon fiber preimpregnated plain cloth and cyanate resin, and the plying pattern is [(±45°) / (0° / 90°)], that is, (0° / 90°) and (+45° / -45°) are staggered.

[0012] Furthermore, the focal plane side supports are made of titanium alloy 3D printing and are hollow thin ribs plus outer skin structures.

[0013] Furthermore, the end of the composite rod is fixedly connected to the focal plane side support by bonding;

[0014] The adhesive used for bonding is J133 composite adhesive.

[0015] Further, the interface module includes a titanium alloy inner screw block and a titanium alloy outer ring;

[0016] The titanium alloy inner screw block is buried in the composite rod, and the titanium alloy outer ring is sleeved on the outside of the composite rod and its position corresponds to the titanium alloy inner screw block;

[0017] The side of the titanium alloy inner screw block is provided with screw holes, and the side of the titanium alloy outer ring is provided with through holes corresponding to the positions of the screw holes. Each functional module is fixedly connected to the composite rod by screws passing through the through holes and the screw holes.

[0018] The titanium alloy outer ring is fixed to the outside of the composite rod by bonding, and the bonding glue is J133 composite glue.

[0019] Furthermore, the location and quantity of the interface modules are determined according to the layout of the functional modules.

[0020] A highly lightweight remote sensing camera focal plane, comprising the highly lightweight remote sensing camera focal plane support structure and a functional module;

[0021] The functional module includes a spliced ​​reflector, a detector, a back circuit and a thermal control module; the spliced ​​reflector, the detector, the back circuit and the thermal control module are all fixed on the main bearing force of the focal plane through an interface module.

[0022] Further, the spliced ​​reflector is connected to the interface module via a reflector bracket;

[0023] The reflector bracket includes a base and a hollow support rod extending from the base. The base is provided with three interfaces, which are distributed in a triangle and are connected to three interface modules respectively.

[0024] The intersection of the support rod and the base is set as point A, and the three interfaces are set as points B, C, and D respectively. The center of the line connecting point B and point C, point A, and point D are collinear. Point B and point A, as well as point C and point A, are connected by a bent and folded thin arm structure to achieve force and heat unloading in all directions within the installation surfaces of B, C, and D.

[0025] Furthermore, the spliced ​​reflector is a mushroom head configuration microcrystalline reflector;

[0026] The microcrystalline reflection of the mushroom head configuration microcrystalline reflector is a structural form of a top plane plus a thin support rod at the bottom. The thin support rod is inserted into the hollow support rod of the reflector bracket and connected by gluing to achieve force and heat unloading of the mirror surface and ensure surface stability.

[0027] Furthermore, the reflector bracket is made of titanium alloy 3D printing, which is a hollow thin rib plus outer skin structure;

[0028] The reflector bracket and the spliced ​​reflector are bonded together by optical structural adhesive.

[0029] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0030] (1) The present invention creatively proposes a highly lightweight remote sensing camera focal plane support structure and focal plane, which can simultaneously meet the three key requirements of the focal plane of a space camera: high specific stiffness, high temperature stability, and strong interface adaptability, thereby solving the technical defects of the existing focal plane;

[0031] (2) The present invention uses a composite rod and a 3D printed high-lightweight structure, so that the weight of the focal plane main load-bearing structure is 5% of that of the traditional design, which has an order of magnitude advantage; the total weight of the focal plane assembly based on the present invention is 1 / 5 to 1 / 7 of that of the traditional design, which greatly reduces the mechanical burden of the camera body, saves the resources of the whole machine, and leaves more room for the main body design;

[0032] (3) The material cost of the present invention is low, the processing technology is simple, the time and economic cost are low, and it is conducive to improving production efficiency;

[0033] (4) The present invention provides a specific structure of parts such as composite rods, interface modules, and reflector brackets, which can effectively improve the convenience of installation and mechanical and thermal stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the focal plane of a highly lightweight remote sensing camera of the present invention;

[0035] Figure 2 This is a schematic diagram of the main bearing structure of the focal plane of the present invention;

[0036] Figure 3 is a schematic diagram of a reflector assembly of the present invention;

[0037] Figure 4 A schematic diagram of the interface module after hiding a composite rod of the present invention;

[0038] Figure 5 This is a structural diagram of the interface module of the present invention;

[0039] Figure 6 Schematic diagram of (a) a titanium alloy inner screw block and (b) a titanium alloy outer ring of the present invention;

[0040] Figure 7 It is a schematic diagram of the focal plane side support structure of the present invention. DETAILED DESCRIPTION

[0041] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0042] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0043] The present invention provides a focal plane main load-bearing structure of a highly lightweight 3D printed titanium alloy support member bonded by a composite rod, which simultaneously meets the three key requirements of the focal plane of a space camera: ultra-high specific stiffness, high temperature stability, and strong interface adaptability, thereby solving the technical defects of the existing focal plane.

[0044] The present invention uses hollow composite rods and highly lightweight 3D printed titanium alloy parts, which are bonded and combined to form the main support of the focal plane; a modular titanium alloy inner screw block and a titanium alloy outer ring combination are used, which are distributed inside and outside the hollow composite rod to form an external interface with uniform size and flexible and adjustable position, which is responsible for the installation and adaptation of various interfaces such as focal plane light (splicing reflectors), machine (structural parts), electricity (detectors and back circuits), and heat (thermal control modules). The spliced ​​reflector adopts a mushroom head configuration and is bonded to the highly lightweight 3D printed reflector support structure through optical structural adhesive to achieve force and heat unloading. The reflector assembly is installed on the main bearing force of the focal plane with the help of a titanium alloy module. The weight of the focal plane support structure of the invention is about 5% of that of the traditional design, which has an order of magnitude advantage; the total weight of the focal plane assembly based on the present invention is 1 / 5 to 1 / 7 of that of the traditional design. Example:

[0045] The focal plane support structure in the present invention is the main focal plane structure of a remote sensing camera. Now, taking the focal plane design of the camera as an example, the specific implementation mode of the present invention is described. According to the summary index requirements of the camera, the total length of the focal plane linear array of the camera needs to be greater than 420 mm, and 7 detectors with a linear array length of 61 mm are required to be optically spliced ​​to meet the ultra-long linear array detection requirements of the whole machine. According to the traditional focal plane design method in the past, the main support form of the focal plane such as cast titanium, carbon silicon carbide, or Invar is adopted. The main load-bearing part of the focal plane alone weighs about 10 to 18 kg. Considering the various components of optomechanical, electrical and thermal, the weight of the entire focal plane is about 35K. There are many disadvantages such as overweight, poor thermal stability (cast titanium), poor interface adaptability, high cost (carbon silicon carbide), overweight, poor specific stiffness (Invar), etc.

[0046] The focal plane of the camera based on the method of the present invention has a main bearing weight of 0.45Kg and a total weight of 7Kg for the focal plane assembly. Taking the focal plane as an example, the implementation method is specifically described:

[0047] The focal plane includes: a focal plane main bearing force 1, a reflector assembly 2, a detector 3, a back circuit 4, and a thermal control module 5;

[0048] The focal plane main bearing 1 includes: a composite rod 1.1, a focal plane side support 1.2; an interface module 1.3; wherein the interface module includes: a titanium alloy inner screw block 1.3.1, a titanium alloy outer ring 1.3.2;

[0049] The reflector assembly 2 comprises: a spliced ​​reflector 2.1 and a reflector bracket 2.2;

[0050] like Figure 1 The main support structure of the focal plane assembly is the focal plane main bearing 1, which supports the optical, mechanical, electrical and thermal components of the entire focal plane, has an interface with the camera body, and also has interfaces for supporting its own components. The reflector assembly 2, detector 3, back circuit 4 and thermal control module 5 are all connected and fixed to the focal plane main bearing 1 through the interface module 1.3.

[0051] like Figure 2 , the main bearing of the focal plane is a combined processing part of composite materials and metal parts. It includes three composite rods 1.1, two mirror-symmetrical and highly lightweight 3D printed focal plane side supports 1.2, and multiple titanium alloy interface modules 1.3 distributed on the composite rods. The composite rod 1.1 is a hollow composite tube with a square cross-section. It is formed by carbon fiber prepreg plain cloth, cyanate resin, and staggered ply. In order to ensure the stiffness and isotropic uniformity of the composite rod 1.1, the ply of the carbon fiber prepreg plain cloth is staggered in the form of (0° / 90°) and (+45° / -45°). The total thickness after plying is 1.6~1.8mm. Figure 7 The focal plane side supports 1.2 on both sides are highly lightweight parts made by 3D printing titanium alloy technology. The part is a hollow thin rib plus outer skin structure. The outer skin is 0.8mm thick, the hollow thin rib is 1mm thick, and the upper and lower skins sandwich the thin rib sandwich layer in the middle, which greatly improves the specific stiffness of the part. An interface with the optical machine body is left on the side, and three bonding interfaces with the composite rod 1.1 are left on the edge. Processing allowances are reserved at the interface position in the printing state, and it is combined with three composite rods 1.1 for processing and bonding to ensure the structural reference. Figure 4 , Figure 5 and Figure 6 The interface module 1.3 includes a titanium alloy inner screw block 1.3.1 and a titanium alloy outer ring 1.3.2. The titanium alloy inner screw block 1.3.1 has 8 M3 screw holes on the side and is buried in the composite rod 1.1. The titanium alloy outer ring 1.3.2 is a thin titanium ring with 8 Φ3.2 through holes on the side and is sleeved on the outside of the composite rod 1.1. The two correspond to each other inside and outside and are bonded to the composite rod by combined processing. They are part of the main bearing force 1 of the focal plane. The position and number of the interface modules 1.3 are mainly determined by the optical splicing layout of the detector assembly 3. For example, if the length of the single-chip detector photosensitive linear array is 61mm and the length of the detector optical splicing overlap area is 3mm, then the main arrangement spacing of the two groups of interface modules 1.3 on the composite rod 1.1 is 61-3=59mm. At the same time, the installation of the back circuit 4 and the thermal control module 5 is taken into consideration, and the auxiliary interface module 1.3 is appropriately added. Due to the use of the form of corresponding inside and outside and combined processing with the composite rod, the interface module 1.3 has excellent interface adaptability and matching. The adhesive used for bonding the focal plane main bearing 1 is J133 composite adhesive.

[0052] like Figure 3, the reflector assembly 2 includes: a spliced ​​reflector 2.1 and a reflector bracket 2.2; wherein the spliced ​​reflector 2.1 is a mushroom-shaped microcrystalline reflector, which is similar to a mushroom shape, with a reflector surface at the top and a thin rod supporting the reflector surface at the bottom. The reflector bracket 2.2 is a highly lightweight part made by 3D printing titanium alloy technology. The part is a hollow thin rib plus outer skin structure, which is mainly composed of two parts, the bottom support and the top hollow support rod; the bottom support contains three installation interfaces, two of which are bent and folded thin arm legs, which can achieve force and heat unloading in all directions within the installation surface; the top hollow support rod is reserved for processing allowance when it is printed. After the size of the thin rod at the bottom of the spliced ​​reflector 2.1 is determined, the inner diameter of the hollow support rod of the reflector bracket 2.2 is prepared, and the two are bonded by optical structural adhesive.

[0053] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0054] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A highly lightweight remote sensing camera focal plane support structure, characterized in that: include: Focal plane main bearing force (1); The focal plane main bearing (1) comprises a composite rod (1.1), a focal plane side support (1.2) and an interface module (1.3); The three composite rods (1.1) are parallel, and the two ends of each composite rod (1.1) are respectively fixedly connected to the two focal plane side supports (1.2), and the three connection points of the three composite rods (1.1) and the same focal plane side support (1.2) are distributed in a triangular shape; The interface module (1.3) is arranged on the composite rod (1.1) and is used for connecting the functional modules.

2. The highly lightweight remote sensing camera focal plane support structure according to claim 1, characterized in that: The composite rod (1.1) is a hollow composite tube with a square cross section; The composite rod (1.1) is formed by interlaced plying of carbon fiber pre-impregnated plain fabric and cyanate resin, and the plying pattern is [(±45°) / (0° / 90°)].

3. The highly lightweight remote sensing camera focal plane support structure according to claim 1, characterized in that: The focal plane side support (1.2) is made of titanium alloy 3D printing and is a hollow thin rib plus outer skin structure.

4. The highly lightweight remote sensing camera focal plane support structure according to claim 1, characterized in that: The end of the composite rod (1.1) and the focal plane side support (1.2) are fixedly connected by bonding; The adhesive used for bonding is J133 composite adhesive.

5. The highly lightweight remote sensing camera focal plane support structure according to claim 1, characterized in that: The interface module (1.3) comprises a titanium alloy inner screw block (1.3.1) and a titanium alloy outer ring (1.3.2); The titanium alloy inner screw block (1.3.1) is embedded in the composite rod (1.1), and the titanium alloy outer ring (1.3.2) is sleeved on the outside of the composite rod (1.1) and its position corresponds to the titanium alloy inner screw block (1.3.1); The titanium alloy inner screw block (1.3.1) has screw holes on its side, and the titanium alloy outer ring (1.3.2) has through holes corresponding to the positions of the screw holes on its side. Each functional module is fixedly connected to the composite rod (1.1) by screws passing through the through holes and the screw holes. The titanium alloy outer ring (1.3.2) is fixed to the outer side of the composite rod (1.1) by bonding, and the bonding glue is J133 composite glue.

6. The highly lightweight remote sensing camera focal plane support structure according to claim 5, characterized in that: The position and quantity of the interface modules (1.3) are determined according to the layout of the functional modules.

7. A highly lightweight remote sensing camera focal plane, characterized in that: A highly lightweight remote sensing camera focal plane support structure and a functional module comprising any one of claims 1 to 6; The functional module comprises a spliced ​​reflector (2.1), a detector (3), a back circuit (4) and a thermal control module (5); the spliced ​​reflector (2.1), the detector (3), the back circuit (4) and the thermal control module (5) are all fixed on the focal plane main bearing (1) through an interface module (1.3).

8. The highly lightweight remote sensing camera focal plane according to claim 7, characterized in that: The spliced ​​reflector (2.1) is connected to the interface module (1.3) via a reflector bracket (2.2); The reflector bracket (2.2) comprises a base and a hollow support rod extending from the base, the base is provided with three interfaces, the three interfaces are distributed in a triangular shape, and the three interfaces are respectively connected to three interface modules (1.3); The intersection of the support rod and the base is set as point A, and the three interfaces are set as points B, C, and D respectively. The center of the line connecting point B and point C, point A, and point D are collinear. Point B and point A, as well as point C and point A, are connected by a bent and folded thin arm structure to achieve force and heat unloading in all directions within the installation surfaces of B, C, and D.

9. A highly lightweight remote sensing camera focal plane according to claim 8, characterized in that: The spliced ​​reflector (2.1) is a mushroom head configuration microcrystalline reflector; The microcrystalline reflector of the mushroom head configuration microcrystalline reflector is a structural form of a top plane plus a thin support rod at the bottom. The thin support rod is inserted into the hollow support rod of the reflector bracket (2.2) and connected by gluing to achieve mechanical and thermal unloading of the mirror surface and ensure surface stability.

10. The highly lightweight remote sensing camera focal plane according to claim 7, characterized in that: The reflector bracket (2.2) is made of titanium alloy 3D printing and has a hollow thin rib plus outer skin structure; The reflector bracket (2.2) and the spliced ​​reflector (2.1) are bonded together by optical structural adhesive.

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